Microtrends: Brad Brach's Splitter

With a mere eight games of Baltimore baseball in the books, we can't make too many concrete observations about the 2015 team. But we can certainly try, and looking at some of the smaller fluctuations — even those among relief pitchers — can give us ideas as to how the season might go. For Brad Brach, the early going might portend better results as the season progresses.

On the surface, Brach has struggled thus far, allowing five earned runs in his 4.2 innings of work. A .563 BABIP will distort any pitcher's results, though, and the peripherals tell a wholly different story: Brach owns a sparkling 2.18 xFIP, mainly because he's punched out six of the 23 batters he's faced. Compared to last year, in which he put up a strikeout rate of 21.2%, that represents a significant improvement, and it's come from one pitch in particular.

A couple months ago, my colleague Matt Kremnitzer noted some changes Brach made in his first Baltimore campaign:

Before this season, Brach had thrown his four-seamer the most, about two-thirds of the time, followed by his slider and splitter. But he threw his sinker 15% of the time last season, which took a chunk out of his four-seam offerings.

After relying heavily on a four-seam fastball for the first three years of his major-league tenure, Brach began to phase it out upon coming to the Orioles. So far in 2015, he's perpetuated that trend:

But he hasn't replaced those heaters with sinkers — his rate of the latter hasn't budged from last year. Rather, he's increased his usage of his splitter:

This has been something of a career-long trend for Brach: As he becomes more and more experienced, he leans more and more on his splitter. With a career SwStr% of 23.6% — well above the 15.5% baseline for the pitch — the pitch has always helped him rack up strikeouts, so throwing it more would certainly help with that.

It's fairly easy to see why Brach's splitter so befuddles batters. Its velocity has only increased:

League-average splitter velocity usually sits at 84 MPH, so 86 makes a sizable difference — one that has undoubtedly assisted Brach in fanning so many hitters.

In addition, Brach's splitter moves differently from most of its contemporaries. In 2014, the average splitter broke 4.5 inches to the right (from the catcher's perspective), and rose 2.5 inches. By contrast, Brach's splitter, since debuting in 2011, has shifted 9.3 inches horizontally, and 0.8 inches vertically. Together with the aforementioned velocity, this unconventional movement makes the splitter a legitimate force, and Brach appears to have finally realized it.

Of course, Brach probably won't stay this good for the whole season. Based on the fact that he walked 11.8% of the batters he faced prior to 2015, I'd say the 4.4% BB% he's posted thus far will regress a bit. Nevertheless, if he continues to utilize his splendid splitter as much as he has, he may progress further as a reliever. After the departure of Ryan Webb and the (early) struggles of Kevin Gausman, the Orioles could use that.

Has the 2015 season just begun? Yes. Will any earnest observations made now look preemptive come October? Probably. But that won't stop us from scrutinizing the inner workings of baseball, and doing what we can to separate the signal from the noise. And in the case of Brad Brach, the former appears to have a hand in what has occurred, and what will occur.